Foaming properties of the complex of chitooligosaccharides and bovine serum albumin and its application in angel cake

The complex of chitooligosaccharides (COS) and protein is worthy of investigation, as COS is an important functional ingredient and the functional properties of protein might be improved after complexation. Using bovine serum albumin (BSA) as the model protein, this work explored the foaming properties and interfacial behavior of COS-BSA complex, as well as its application as a substitute for egg whites in angel cake. The effects of pH and mixing ratio (r) on the foam properties and interfacial behavior of COS-BSA complex were studied using dilute solution. And the effects of the COS-BSA substitution rate on the physical properties and microbial storability of the cake were studied. Compared with BSA, the foaming capacity and foam stability of COS-BSA complexes were significantly improved in the pH range of 3.0–10.0, and both the foaming capacity and foam stability of COS-BSA complexes at pH 7.0 were in the order of r0.5 ≥ r0.25 ≥ r1.0 > r2.0 > BSA > COS. Angel cake with the COS-BSA substitution rate of 25% had the best physical properties, in which COS and BSA had a synergistic effect on the specific volume and texture of the cake. The substitute of COS-BSA complex for egg white in angel cake significantly inhibited microbial growth during storage. This work provided COS-BSA complex as a substitute for egg white in cake making, and COS-BSA complex improved the physical properties of cake and inhibited microbial growth.